This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Scientific Progress and Future Research Directions (June 2001), indicate that sources of stem cells include bone marrow, cord blood, peripheral blood, blood vessels, the cornea and the retina of the eye, brain, skeletal muscle, fat, liver, skin, the lining of the gastrointestinal tract, pancreas and dental pulp. Methods and apparatus have been developed to remove stem cells from some of these areas of the mammalian body. But, the quantity of stem cells and degree of differentiation is often a therapeutic problem.
Cord blood harvest and storage represent an important source of a good quantity of autologous stem cells; however, cord blood stem cells more often than not have hematopoietic lineage commitment. Furthermore, these cells are limited in number as a single placenta represents a one-time donation, which can often be limited in the number of stem cells provided. In addition, cord blood and its hematopoietic cell isolate have only had anecdotal success in orthopedic applications, likely because the of the significant degree of hematopoietic commitment of these stem cells and the fact that other phenotypic defined stem cells in the isolate do not have additional cells required for ancillary support and differentiation at the site of injection for injury and pathology treatment.
Bone marrow aspirates are another major source of stem cells, but similar to cord blood stem cells they are largely committed along the hematopoietic lineage giving rise to more blood cells. Investigations are still ongoing with respect to various orthopedic and other therapeutic needs. Bone marrow stem cells can be isolated to varying degrees and expanded in culture at various processing centers to augment cell numbers, but this can create a significant time delay and likely decrease cell efficacy limiting their clinical implementation.
Fat derived stem cells are common in the equine industry but the number of cell culture passes of purified stem cells from adipose sources necessary to get sufficient numbers and the loss of stem cell receptor profiles with the expansion process has undermined their clinical success.
In children and teenagers, unerupted third molars represent an additional opportunity to obtain a potentially therapeutic quantity and quality of stem cells from dental tissues that are currently discarded after extraction. Methods to preserve these discarded molars are proposed and currently at various stages of commercialization. In regards to removal of stem cells from unerupted molars specifically, such methods and apparatus include U.S. Patent Publication No. 2008/0176325 to Bowermaster, et al., the contents of which are incorporated herein by reference. In all of these cases, the dental stem cells are removed from the tooth tissues and the surrounding soft tissues containing growth factors and other important cells are discarded.